OnTriggerEnter can't detect my Transform tag

I'm making a simple zombie survival game. I've a problem with this code, this script detect only one trigger, but the other, no.

 #pragma strict
 
 var health = 100;
 var attack = 10;
 var delay = 5;
 var scream : AudioClip;
 var player : Collider;
 
 function OnTriggerEnter () {
 
     if (player.gameObject.tag == "ZombieFlame") {
         gameObject.Find("Flame").SendMessage("OnTriggerEnter");
     }
 
     if (player.gameObject.tag == "Zombie") {
         Attack ();
     }
 
     if (health == 0) {
         Debug.Log("Die!");
         Lose ();
         }
     }
 
 function Attack () {
     health -= attack;
     Debug.Log("Under attack!");
     audio.PlayOneShot(scream);
     yield WaitForSeconds(delay);
     Loop ();
 }
 
 function Loop () {
     OnTriggerEnter ();
 }
 
 function Lose () {
     this.active = false;
 }

My script detects the "ZombieFlame" but not the "Zombie", that Transform have already the tag, I don't know what is going on. It's checked like Trigger, too.

Any help will be gladly received, thank you very much!